Hook and loop fastening structures may be used in various applications to secure objects adjacent each other. For example, hook fastening strips may be molded onto a surface of a foam bun of an automobile seat, and loop material may be provided on an inner surface of an automobile seat covering to engage the hook fastening strips and secure the seat covering to the foam bun. Flexible hook fastening strips may be utilized adjacent portions of the foam bun having contours, and straight hook fastening strips may be utilized on straight portions of the foam bun, such as longitudinally down the center of the bun.
FIG. 1 illustrates an embodiment of a mold 10 for forming the foam bun of a particular automobile seat. The mold 10 includes trenches 12, 13 for receiving the hook fastening strips 21, 22, respectively, prior to injection of the foam for forming the foam bun. An operator disposes a straight hook fastening strip 22 within a straight trench 13 and a flexible hook fastening strip 21 within each curved trench 12. To hold the hook fastening strips 21, 22 in the trenches 12, 13 and to align each strip 21, 22 properly within each trench 12, 13, the trenches 12, 13 may include a magnetic surface and the hook fastening strips 21, 22 may include a monofilament having magnetic properties (e.g., carbon steel or iron) formed within the fastening strips 21, 22.
Prior art flexible hook fastener strips such as the fastener strips 21 shown in FIGS. 1 and 2A-2D are die cut into the shape and length of the trench 12, which limits the fastener strips to use only with trenches having that particular shape and length. In addition, a covering 23 is disposed over the hooks to prevent foam from seeping between the hooks. However, an operator has to remove this covering 23 from a base 24 on which the hooks are disposed after removing the formed foam bun from the mold 10, which results in an extra manufacturing step for the operator and wasted material for the manufacturer. Furthermore, the known fastener strips 21 are flimsy, making them difficult for the operator to manipulate when disposing them within the trenches 12.
Straight fastener strips 22, such as those disclosed in U.S. Published Patent Application Number 2007/0240289 and shown in FIG. 3, provide a sufficient level of stiffness in a plane perpendicular to an upper surface of the fastener strips 22, but these fastener strips 22 lack flexibility in a plane containing the upper surface of the fastener strips 22. Accordingly, these strips 22 can only be used in substantially straight trenches. In addition, these length of these strips 22 are cut (or formed) to be substantially the length of the trench in which the strip 22 is to be disposed. Accordingly, manufacturers that use the strips 22 have to stock different length strips 22 for use in trenches having different lengths.
The Assignee of this application also has developed another type of fastener strip assembly 25, as shown in FIG. 4, which includes a plurality of straight fastener strips 28 that are joined together in an end-to-end relationship by an elongated connecting member 29. Like the known fastener strips described above, the fastener strip assembly 25 according to various embodiments has a total length that is substantially the length of the trench in which the fastener strip assembly 25 is to be disposed. Thus, fastener strip assemblies 25 having varying lengths are assembled to accommodate trenches having varying lengths. Furthermore, the fastener strips 28 used in the fastener strip assembly 25 are cut to varying lengths to accommodate fastener strip assemblies 25 to be used in trenches having varying radii of contour. For example, for trenches having a greater radius of contour, the fastener strips 28 used in the fastener strip assembly 25 have a shorter length to allow the fastener strip assembly 25 to follow the contour. Similarly, for trenches having a lesser radius of contour or straight trenches, the fastener strips 28 used in the fastener strip assembly 25 can have a longer length. Thus, this arrangement results in the need to assemble fastener strip assemblies 25 using fastener strips 28 having different lengths and to assemble fastener strip assemblies 25 having different overall lengths to accommodate various trench lengths and curvatures.
Thus, a need in the art exists for an improved system and method for installing hook fastener strips within straight and curved trenches of a mold assembly and provides for increased efficiency in the manufacturing and installation process.